Our proposed interdisciplinary exploratory study, prepared in response to PAR-10-137, focuses on a significant yet little explored problem: how best, conceptually and methodologically, to integrate use of age-period-cohort (APC) analysis to advance understanding of societal determinants of trends in the magnitude of health inequities. Drawing on social epidemiology and political sociology frameworks and methods, and also new advances in APC models, our innovative theoretically-motivated case example concerns what we term the Jim Crow geography of mortality, a topic on which scant empirical work exists. The two-fold contributions of our project will be: (1) conceptual, providing new insights and guidance regarding use of APC models to analyze how policy changes can influence population health and health inequities; and (2) substantive, given the paucity of research on the health impact of the abolition of legal racial discrimination by the 1964 US Civil Rights Act. Study outcomes will be all-cause and cancer mortality (total and <65 y (premature)) and infant death (<1 y); the two sets of disparities pertain to comparisons of the US black vs white population, and the US black population in Jim Crow vs non-Jim Crow states, analyzed in relation to spatiotemporal scale (lifecourse, historical generation, spatial effects) and level (state, county, individual). Our Specific Aims accordingly are: (1) Aim 1: Conduct exploratory and graphical APC analysis of a database comprised of 1960-2006 county-level US black and white mortality and denominator data linked to annual county median family income data and newly linked to data on state Jim Crow status (i.e., did vs did not have legalized racial discrimination prior to te 1964 US Civil Rights Act); steps include creating detailed A, P, and C categories, calculating the study outcome annual rates and disparities, and performing APC tabulations and graphical analyses; Aim 2: Explore use of diverse APC modeling approaches to analyze the impact of the abolition of Jim Crow on the specified mortality outcomes: (a) theoretically, in relation to etiologic and statistical assumptions, and (b) empirically, using: (i) a widely-used conventional solution to address the identification problem due to linear dependence of A, P, and C, by assuming only 2 of the 3 affect the outcome; (ii) a new - and debated - statistical approach, called the intrinsic estimator; and (iii) an approach based on generalized linear mixed models which can be extended to address group disparities and spatial effects; and (3) Aim 3: Disseminate findings and use results to inform preparation of an NIH R01 grant to conduct APC analyses of the impact of policy change on the magnitude of health inequities. The proposed project thus will directly address key objectives of PAR-10-137, and also Healthy People (HP) 2010 and HP 2020, since it will conduct theoretically-motivated empirical tests of APC approaches relevant to understanding the impact of policy, social context, levels, lifecourse, and racial discrimination on the magnitude of health inequities, substantively in relation to Jim Crow and more broadly for other policies as well.